How fast should a stock sc be able to go?

Porsche80 · Porsche80's Garage

Now I know this is an open end question, but what should be the max mph of a stock 1980 SC(not the manufactures data). I got mine up to about 120mph and it would go no faster. My wrench said maybe the rear end or trany gears were changed.

Any thoughts ?

madmmac · madmmac's Garage

Were you at redline on the tach?

schoward · 01-04-2008, 07:10 PM

Are you sure you are getting full throttle? Many stories of throttle rod linkage issues on older cars - out of adjustment, etc.

Danny_Ocean · 01-04-2008, 07:11 PM

120 ~ 130 sounds about right. 145 for 930's, I think.

Porsche80 · Porsche80's Garage

No redline. Pedal was to floor. Engine just rebuilt completely. Heads ported, new SSI's and performance muffler

the · 01-04-2008, 07:13 PM

138-140

Car Guru · 01-04-2008, 07:16 PM

I had my bone stock '88 3.2 Cabriolet up to 130 on accident, was only trying to go about 120, but glanced down and the needle was slightly past 130 ish. These Carrera's are not the fastest things off the line, but they go like a demon after 60-70 mph. Car was still pulling really good too! My OM says the car is capable of 149 (Carrera) & 157 for (930). I would be curious my self to know what some of you have hit on a track or closed course

-Ryan

madmmac · madmmac's Garage

How many miles are on the rebuild?

Agree with the not getting full throttle possibility.

Easy to check, have someone floor it, look in the engine compartment and the throttle opening should just be short of the stop.

SC should be good for 135-140mph.

dipso · 01-04-2008, 07:27 PM

Stock 2.7 135 mph slight downhill. gets a little iffy about 120.
Brand new toll roads out here in so cal are nice for speed runs.

Hugh R · 01-04-2008, 07:40 PM

I've read that our speedos are notoriously optimistic by about 10 mph at speed. Mine was according to my GPS, when North Hollywood Speedometer overhauled it, they recalibrated it.

billybek · billybek's Garage

I have seen + 110 mph also "by accident" and the 83 had a lot of pedal and rpms left.
Still getting to know this car so I can't say for sure.

fitchn · 01-04-2008, 07:57 PM

120 seems awfully low to me, when my 79 sc was bone stock, smog pump and all, I easily saw 145 on the speedo on a drag strip (used for warmups before a short autocross course) and it didn't feel at all like it was done yet. Still pulling firmly.

billybek · billybek's Garage

Does it roll easy? Anything dragging (brakes CVs trans)? Timing, bad fuel etc.......?

rouxroux · 01-04-2008, 08:21 PM

Now if it was only a Targa..........

gshiwota · 01-04-2008, 08:38 PM

My '82 SC maxes out at 85 MPH (I still have the original 85MPH speedo).

gshiwota · 01-04-2008, 08:45 PM

My '82 SC maxes out at 85 MPH (I still have the original 85MPH speedo).

jonbot · 01-04-2008, 09:54 PM

I had my '79 SC up to 125 the other day, and it didn't feel like it had any ideas of slowing down.

PeterRT · 01-05-2008, 12:34 AM

In period it was tested at 143 mph. If you weren't going uphill into a strong headwind you're probably missing about 70 horses.

cterror · 01-05-2008, 01:16 AM

my 80sc with stock 3,2 replasement engine does 255km/h on speedo. gps showed 238km/h at the same time, so there is an big gap in actual vs speedo with my small tires. it revs to the limiter in 5th gear with 205/60-15 rear tires. 238km/h equals to about 145 mph. your 120 seems very low indeed. what size tires do you use?
Oh... and my car is narrow body with no rear wing.

Targa4now · 04:28 AM

120 mph is LOW for an SC. I've hit ~130mph with 1200 left on the tach in 81 Targa (top on of course). Top end in my ride is probably 140mph; not bad for a 27 year old 911SC!